Pen 7
This is my
attempt to produce a pen that solves the problems I find annoying with
my previously owned fountain pens.
I produced the following design aims for a fully customized (Kitless)
design:-
1. It should have a #6 nib as I think this is a smoother writer than a
#5 nib.
2. It should be as small as possible, to fit in my shirt pocket
average depth of my shirts is 5 inches.
3. It should weigh less than 25 grams, the weight of my present
"Carry Pen" (#5 Euro kit pen).
4. The Cap/Body should be a smooth interface so there is no step as
this step annoys me.
5. The Section should have a Section Body thread long enough to ensure
it extends into the body of the pen past the shoulder where the cap
closes on to improve the strength of the body at this shoulder.
6. The housing should be let into the section to a depth that gives a
smooth front surface rather than the usual step.
7. The Cap should post with a positive screw action as push fits tend
to fall off in use.
8. The pen should have the smallest possible body/cap diameter – (A
Trial thin Cap proved satisfactory from a rigidity and strength point
of view )
9. The end of the body should be smooth and semi-spherical for shirt
pocket comfort.
10. The clip should be slightly longer than normal to make it more
secure in the shirt pocket.
11. The clip should not suffer, as many clips do, from losing its
clipping tension (Use a Spring Steel Ring).
12. The fixing of the clip to the cap should not slip and will cause
the minimum increase to the "in pocket" length of the pen.
13. Body Cap thread to be 2.5 Turns of 3 start to minimize the force
on thread when capping or posting.
14. The 3 start body/cap threads should be made impossible to
"Cross-Thread" by design.
15. All external metal parts, where possible, to be Stainless Steel
for durability.
16. Converter to be vacuum type, (as my experience says ink flows
better than with a twist converter).
The 1st & 2nd Pictures show the pen I made using my Sieg Metal Lathe
and Mini Mill.
The pictures show that the cap flows directly into the body (both
capped and posted) without a step.
Both ends of the pen are smooth hemispheres which I turned by setting
the cross slide DRO to:-
D/2 x cos A
Then turned, using the top slide DRO, to:-
D/2(1 - sin A) when measured from the front of the hemisphere
Where D was the maximum Diameter of the hemisphere and Angle "A"
was selected so that the average material removed was approximately a
0.05 mm(2 thou' inches) step
Just over 50 cuts were made for each hemisphere and then they were
smoothed and polished with Micromesh followed by Metal Polish.
This worked well with the assembled finial and Stainless Steel Insert
Nut with no problems at the interface between the acrylic and steel.
The custom clip was machined out of 3/8 inches free cutting Stainless
Steel rod using the metal lathe, the mini mill and then files. This
was then polished with Emery cloth followed by Micromesh and metal
polish.
An Antique Spring Steel Clip, purchased on E-Bay, was modified by
grinding off all but 15 mm from the ring and then shaping the
"Peg" so that it slid into a #55 drilled hole in the Stainless
Steel Custom Clip. Barbs were ground along this peg and it was glued
into the clip with epoxy.
The 3rd of my pictures, "PARTS", shows further details and
dimensions of the pen I have entered.
